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By Bill Elverman

Randy and Kenny Robison have visited every coal mine that would let them in the door, to survey the best mining practices. The brothers have spent nearly their entire lives working in coal operations. The Robison’s started out on lube and grease trucks and worked their way up to respected industry leaders in Alabama. The Robisons have owned MS&R since 1989. Since then, they have created a niche for themselves in providing coal for Alabama’s metallurgical coal market. A great deal of the knowledge the Robisons have amassed throughout the years has come from observing — taking note of what works and what does not. In early spring 2004, they commissioned a Komatsu America PC3000 Super Shovel. Outfitted with a backhoe attachment and a 16-m3 (21-cu yd) bucket, MS&R’s PC3000 is currently one of the largest mining excavators working in Alabama.

Jan 1, 2005

By A. Anani, K. Awuah-Offei

"Accounting for changing duty cycles in equipment matching maximizes equipment utilization and productivity. The objective of this study is to investigate if the optimal number of shuttle cars for a particular panel width is optimal in different segments of the panel. In this study, discrete event simulation (DES) is used to determine the optimal number of cars that maximizes productivity in each segment. Data from a real-life mine is used to validate the model. The study shows that the optimal number of cars for the entire panel may not be optimal for some of the defined segments. INTRODUCTION Fleet optimization is important for efficient mine management. Deploying the optimal fleet minimizes the capital and operating expenditure for particular operating conditions and production targets. In an operating mine, with an already existing fleet, deploying the optimal fleet maximizes productivity or minimizes production cost with the available resources. Hence, a lot of research has focused on how to determine the optimal fleet size for a mining operation, given particular operating conditions. Mine managers and engineers have successfully used discrete event simulation (DES) to determine the optimal fleet size in mines (Michalakopoulos, Roumpos, Galetakis, & Panagiotou, 2015; Awuah-Offei, Osei, & Askari-Nasab, 2011; Ben-Awuah, Kalantari, Pourrahimian, & Askari-Nasab, 2010; Govinda Raj, Vardhan, & Rao, 2009; Yuriy & Vayenas, 2008; Kwame Awuah-Offei, Temeng, & Al-Hassan, 2003). In most cases, the published work on this topic involves determining the number of hauling units to be matched to a loading unit. Many of these examples involve truck-shovel optimization. There are, however, some underground mining examples. For instance, we recently concluded work that involves fleet optimization in underground room and pillar (R&P) coal mining (Awuah-Offei & Anani, 2015). Generally, when DES is used in fleet optimization it involves three steps: (1) Build a valid model of the mining system capable of predicting the required outputs with varying fleet composition; (2) Design and conduct experiments that vary the fleet composition across all feasible options; and (3) Determine the optimal fleet based on the results of the simulation experiments. A major decision in the first step is which outputs should be modeled. Some examples in the literature include productivity, unit cost, loader utilization, queue length, and hauler waiting times (Awuah-Offei et al., 2011; Govinda Raj et al., 2009; Kwame Awuah-Offei et al., 2003). Often, more than one of these outputs are simulated and considered as the objective function of the optimization."

Jan 1, 2016

By Aline Tatom

This paper presents numerical and experimen¬tal results dealing with the application of ferric ion oxidation of uranium in acidic media. Conclusions are derived from matching numerical results to experimental data taken on one-dimensional laboratory leaches using ore from a South Texas Coastal plain deposit. Since the numerical results can be made quite general, we are able to extract and quantify the effects of oxidant concentration, flow velocity, mass transfer, chemical kinetics, and competitive oxidant consumers (pyrite and molybdenite) on the experimental results. Our results suggest that the leaching of uranium is a mass transfer controlled while that of pyrite is kinetically controlled.

Jan 1, 1981

By Robert E. Gray

The vat leaching operation at the Yerington Mine was started in October, 1953. The original plant facilities consisted of primary and secondary crushing, eight leaching vats, precipitation launders, sulfuric acid plant and the necessary maintenance, warehouse and administrative facilities. By 1961, 35,000,000 tons of oxide ore had been removed from the mine exposing the underlying sulfide ore body. A 5,000 ton per day concentrator was constructed and put into operation to treat the sulfide ore in November, 1961. The original crushing plants were used for both oxide and sulfide ores. By adding a third crushing shift for six days per week, the treated ore was increased from 12,000 to 17,000 tons per day. To balance the oxide and sulfide ore reserves, the concentrator was expanded to 13,500 tons per day in 1967. Again, no additional crushing facilities were added. It was anticipated that the treatment rate of oxide ore would be reduced from 12,000 to 9,000 tons per day. Instead, the addition of two crushing shifts per week, and improved operating procedures, increased the treated ore to 26,500 tons per day, 13,000 tons to the vat leaching and 13,500 tons to the concentrator.

Jan 1, 1975

By Chee S. Theng

As the 2017 president of the Society for Mining, Metallurgy & Exploration Inc., I am pleased to present the 2017 issue of the Transactions of the Society for Mining, Metallurgy & Exploration Inc., Vol. 342. A significant portion of the contribution that we make as a professional society is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of the American Institute of Mining, Metallurgical and Petroleum Engineers (AIME). Those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2017 Transactions contains some of the most interesting research and insights from the past year and features an international slate of authors spanning industry, academia and government. Papers include the latest findings from the U.S. National Institute for Occupational Safety and Health (NIOSH), a special review article on Heap Leach Modeling, and articles from two Special Issues on Rare Earths. The 2017 Transactions consists of a total of 54 technical papers, encompassing all 21 papers published in 2017 in the Technical Papers Section of Mining Engineering (Vol. 69) and all 24 papers published in 2017 in Minerals & Metallurgical Processing (Vol. 34). Additionally, this volume contains 9 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All of the technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our Publications staff. As the 2017 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2017

By W. J. Wolfe

Using a combined fire assay-atomic absorption method, gold determinations with a minimum detection limit of 5 ppb were made on 345 samples of Early Precambrian felsic plutonic rocks collected 2 2 from intrusions ranging in size from 4 km to 88 km and in composition from syenite to granodiorite. Gold levels in unmineralized stocks are consistently below the 5 ppb detection limit of the analytical method used. In contrast, analyses of samples from stocks containing gold mines within their borders and in nearby metavolcanic-metasedimentary host rocks show a strongly skewed trace element gold population with a substantial percentage of gold values exceeding 5 ppb and ranging as high as 320 ppb. The data indicate that (1) ore-stage hydrothermal metasomatism has produced widespread Au enrichment in Precambrian intrusions that host epigenetic vein-type gold deposits, and (2) geochemical Au analysis of samples collected from 30 to 50 randomly distributed sites can be used to estimate the gold exploration potential of stock-sized bodies and to outline internal patterns of Au variation which may be useful in directing exploration to particular contacts or portions of a stock. The results do not conclusively indicate unusually high Au content in primary unaltered igneous rocks.

Jan 1, 1975

By J. Klemenic

This paper presents an analysis of gold production and prices over an extended period. Production patterns are provided for the world as a whole and for the five major producing countries. Gold prices as a function of interest rates, as measured by municipal bond rates, are given for the period 1947 to the present. World gold production has had a phenomenal increase since 1980, with the exception of South Africa, all major producing nations participated in this increase, even though the price of gold generally has been decreasing since the high level attained in 1980.

Jan 1, 1993

By J. C. Ashby

Electric utility response to certain amendments of the Clean Air Act has resulted in a production of several types of alkaline coal combustion byproducts. Alkaline combustion byproducts are gaining increasing usage for acid mine drainage mitigation as research leads to a better understanding of their beneficial applications. Since January of 1997, Mettiki Coal Corporation has been injecting alkaline flue gas desulfurization material from Virginia Power's Mt. Storm Unit #3 wet limestone scrubber into abandoned portions of the active Mettiki mine. This paper provides an overview of the key design, transportation, regulatory, and environmental issues faced in the project.

Jan 1, 1998

By C. Zhou, B. Whisner, J. Carr

Proximity Detection Systems (PDSs) are used in the mining industry for protecting mine workers from striking, pinning, and crushing injuries when they work in close proximity to heavy machines such as continuous mining machines (CMMs). Currently all Mine Safety and Health Administration (MSHA) approved PDSs are magnetic field based systems which can be influenced by the presence of wire mesh that is commonly used for supporting roof and ribs in underground coal m ines. In this paper, researchers at the National Institute for Occupational Safety and Health (NIOSH) characterize the influence of the mesh on the performance of magnetic PDSs by measuring the magnetic field difference around a CMM caused by the presence of the mesh. The results show that the magnetic fields are generally enhanced by the mesh which causes the PDS detection zones to be increased correspondingly. It was discovered that the fields around the joints of two mesh sections have the greatest enhancement and thus deserve more attention. In addition, it is found that the presence of mesh can also cause a variation in the generator current. The influence of mesh is characterized by the change in the generator current with respect to the distance between the generator and the mesh. It was found that the generator current change caused by the mesh can be significant (on the order of ten) when the mesh is extremely close to the generator (e.g, less than 1 cm) and is negligible when mesh is relatively far (greater than 0.15 m). The findings in this paper can be used to develop guidelines and best practices to mitigate the influence of mesh on PDSs. INTRODUCTION The Mine Safety and Health Administration (MSHA) requires operators of underground coal mines to equip place-changing continuous mining machines (CMMs) with proximity detection systems (PDSs) to protect mine workers from striking, pinning and crushing injuries when they work around these heavy machines. Although a variety of technologies can be implemented for proximity detection, the magnetic-field-based PDS that was originally developed at the National Institute for Occupational Safety and Health (NIOSH) has shown great effectiveness in challenging mining environments and currently all MSHA-approved PDSs are magnetic-field-based systems. As shown in Figure 1, a magnetic PDS typically includes two major components----the magnetic field generator and the Miner Wearable Component (MWC). Magnetic fields are generated by injecting a high electric current into a ferrite-rod antenna sealed in the generator. The magnetic field strength detected by an MWC varies with the distance between the MWC and the generator. In a typical PDS, multiple generators are mounted on different locations of the machine. The relative location/zone of an MWC is determined based on the field strengths from different generators picked by the MWC. Ideally, for a PDS to work properly in the underground, the magnetic fields generated by the different generators should be stable and not vary with the environment, as the system would interpret any variation of the magnetic field as a result of the distance change between the machine and the miner wearing the MWC. In reality, however, this is not always the case since magnetic fields can be altered by a number of environmental factors such as the presence of steel wire mesh that has been widely used in underground coal mines for supporting roof and ribs In this paper, the influence of mesh on the PDS performance is investigated and the magnetic field change caused by the mesh is measured.

Jan 1, 2019

By Corey Vaughan

Unplanned shutdowns from abrasive wear part failure in crushers, chutes, and slurry pipe assets can cost millions in lost production and reactive maintenance. 2Censor patented sensor technology enables real time abrasive wear monitoring of mineral processing equipment, turning passive assets into smart, data driven components. Wireless sensors embedded in liners and pipework transmit wear data live to operators, allowing for predictive maintenance, safer scheduling, and optimized asset life. This paper will present global case studies showing reductions in downtime, increased throughput, and improved maintenance accuracy. The system is ready to retrofit, neutral to original equipment manufacturers, and proven across more than twelve countries in abrasive wear liners and slurry pipe applications.

Feb 22, 2026

By Jim Baumann

Deposited millions of years ago in irregular paleokarstic channels, Jamaica’s extensive bauxite deposits provide good quality ore for alumina production and subsequent aluminum smelting. Bauxite mining operations are critical to the Jamaican economy. It accounts for a large percentage of Jamaica’s export earnings. Bauxite production in Jamaica accounts for about 10% of the world’s output each year. Bauxite deposits in Jamaica lie close to the surface. They can be extracted using standard surface mining techniques. The deposits occur in scattered pockets across the country’s rugged landscape. So it was necessary for two of the country’s major mining and refining operations to implement cost effective methods for the acquisition and management of bauxite reserves and surface ownership distribution rights.

Jan 1, 2002

By M. P. Meehan

The purpose of this paper is to present the key elements in a system; study of the electrical system for a timing and/or tilling operation. The ability of an electrical system to function in a reliable fashion at its proper levels is essential for an operation to be successful. A system study consists of a load study for determining the capability of the electrical network to provide power to the various loads and a short circuit study for determining the capability of the electrical protective equipment to properly protect against fault conditions. The sequence of events in a system study is data acquisition, determining the electrical parameters and analyzing the ability of the system to meet these requirements. If the system is small, herd calculations will be the manner in which the study will be conducted; if it is large then commuters will be used. A load study has as its objectives the determination of the capability and reliability of the source of power, transformers and conductors to satisfactorily deliver power to the loads at an acceptable voltage level. The Information required is a single line diagram showing the source, transformers, conductors and loads.

Jan 1, 1980

By A. B. Cecala

The US Bureau of Mines performed a study to determine optimal locations for longwall face methane monitoring equipment. Longwall face ignitions continue to be a concern to the US coal mining industry. Gains in ignition control technology have been somewhat negated by advances in longwall productivity. More reliable, heavy duty longwall face systems generate higher production rates and increase methane liberation rates. These rates will likely continue to rise as further coal production increases occur. Efforts will continue in the areas of methane drainage, methane containment and methane dilution. In addition, more effective face methane monitoring is needed. As technology continues toward automated longwall panels, the importance of monitoring for methane at the shearer becomes even more significant. Since the primary face ignition source is the shearer mining machine, the Bureau ran tests to determine the best location to take methane readings on the shearer. This information, in conjunction with data obtained from field studies, provides a knowledge base for selecting optimum face methane monitoring locations.

Jan 1, 1995

By Lena Paar

"Underground construction poses certain challenges for all parties involved because the actual ground conditions are often unpredictable. Highly complex projects like tunnel construction are affected by various uncertainties. To address this complexity, the construction contract has to be flexible enough to be adapted to the actual conditions (e.g. divergent ground conditions, work delays). However, the adaptation of a tunnel construction contract does not guarantee the absence of a margin of interpretation. The perfect construction contract is an illusion because ex ante statements of the actual ground conditions are not feasible. This paper will discuss contractual parameters that must be considered in order to enable an effective adaptation of the contract during excavation. It is therefore necessary to discuss the following topics: decision-making competence, variable remuneration, fair-risk allocation, value engineering and partnering between client and contractor. INTRODUCTION Thinking of tunnel construction processes, engineers’ first (or at least second) association is about ground conditions. When constructing under the surface, the project is directly related to the ground conditions; however, ground conditions are known fairly well in advance. The estimated conditions can be the same or can also differ from the existing ones. A clear view of the conditions is possible only by driving through the section. What Hoek calls “Geological unpredictability which is guaranteed to provide some surprises in even the simplest tunnelling job” is, in addition to contractual issues, one of two critical aspects of modern tunneling (Hoek 1982). Almost no research tries to figure out, what flexibility in this context means and how to approach it in the contracts. Papers dealing with the New Austrian Tunnel Method (NATM) pose some principles to meet the requests for flexibility (cf. Austrian Society for Geomechanics 2011). However, it remains unclear how to create contracts in order to make them “flexible” enough to react to divergent ground conditions."

Jan 1, 2016

By J. D. Miller, C. L. Lin

Filtration of fine particles involves filter cake formation and removal of surface moisture by drawing air through the porous structure. Accurate assessment of the transport properties of porous media (in this case, filter cake) is of major importance in the development of improved filtration processes. Implications from these studies are important in the design and operation of filtration equipment in order to enhance the efficiency of this important solid-liquid separation process. The microstructure and connectivity of pore space are important features necessary to describe detailed fluid flow phenomena in filter cake during fine particle filtration. In this regard, 3D characterization of pore structure is essential. The pore structure has to be described by parameters which are of special relevance to the interpretation of fluid transport phenomena. These parameters should be based on directly measured variables of the pore system and not inferred from indirect variables (such as those determined empirically from transport processes) valid only for a particular pore structure. In this way fundamental relationships between pore structure and fluid transport at the microstructure level can be described. In order to achieve this level of sophistication the three-dimensional interconnected pore structure of filter cake must be determined. Study of fluid transport phenomena in filter cake using x-ray microtomography to characterize the complex three-dimensional pore geometry is discussed. On this basis the Lattice-Boltzmann (LB) method is used to simulate and to establish a fundamental relationship between pore microstructure and effective transport coefficients.

Jan 1, 2002

By J. Pinkley

DSI DYWI Rock Dust application is aiding in enhancing safety and productivity in underground coal mining. DSI DYWI Rock Dust combines wet dusting technology and polymers to allow for drying and lift characteristics for rock dusting. DSI DYWI Rock Dust typically dries within 24 to 48 hours depending upon the mine air velocity and humidity. The DSI DYWI Rock Dust Applicator Machine is a completely hydraulic unit. The DSI DYWI Rock Dust Applicator machine allows for batching of product and face spraying operations in permissible locations. The DSI DYWI Rock Dusting Applicator Machine fits in one half of a battery or diesel scoop bucket for ease of transport. It is completely hydraulically powered by the PTO circuit. The DSI DYWI Rock Dust Applicator unit requires a scoop operator, and a person to operate the spray wand, simple operation with two personnel. The first demonstration was at an underground continuous miner room and pillar coal mine which produced a pilot test period opportunity, which proved to be successful, and has now been in full launch mode with the US underground coal mining industry. A typical batch of operation allows for 250? of roof and rib (19? wide by 6? in height) coverage of DSI DYWI Rock Dust application. The DSI DYWI Rock Dust Applicator contains a hydraulic powered air compressor which allows for 30-50% more coverage per batch by improved dispersion of product via air assist spray nozzle. DSI DYWI Rock Dust will add approximately $0.02 to $0.04 per clean ton of coal cost to the mining operation over traditional rock dust cost depending upon mining height.

Jan 1, 2012

By A. R. Wilde

The Muruntau gold deposit is situated in the Kyzyl Kum Desert of Uzbekistan. It is currently being mined in the world's largest open pit gold mine with production believed to be of the order of two million ounces per annum. The open pit measures about 3.5 by 2.5 km and extends to a depth of 350m. The gold ore resource in the Muruntau deposit, including production, is about 170 million ounces of gold (Anonymous, 1996). This paper presents a summary of the deposit geology and its regional geological setting. Information used in this paper has been generated from observations made on two visits to the mine and its environs, and a review of the Russian-and English-language literature.

Jan 1, 1999

By A. L. Crandell

The Cortez Mining District has had a long history of mining activity dating back to 1862 as previously reported (1) (2). More recently Cortez Gold Mines (i) has operated a cyanide leach, counter current decantation (CCD) recovery gold mill from January 1969 to February 1976. This type of plant has been standard in the U.S. for treating higher grade finely disseminated gold in Carlin type ores. The mill was initially operated from 1969 to 1973 at 1520 tonnes per day on oxidized ore from the Cortez ore body. Starting in 1973, the mill was operated at 2050 tonnes per day on softer, less oxidized, high clay ore from Gold Acres which is located 13 kilometers to the west of the Cortez installation. In February of 1976 the oxidized portion of the ore body at Gold Acres was depleted and the mill ceased operation. Successful heap leaching of the lower grade portion of the ores was practiced at both Cortez and Gold Acres to supplement the milling operations. Much valuable experience was gained in the operation of these two heap leaching programs and is well described in an earlier publication (3). Releaching of the ore heaps at Gold Acres and Cortez was continued with a limited crew from 1976 to 1979.

Jan 1, 1986

By Charles S. Robinson

The Henderson ore body is east of the Continental Divide in the Front Range of the Colorado Rocky Mountains about 50 miles west of Denver. The ore body is being developed for mining by workings that extend more than 3500 feet below the topographic surface. During construction of the mine workings, ground water in fractures in crystalline rocks has been encountered. From 1969 to 1973, Charles S. Robinson & Associates, Inc., in cooperation with the engineering and geologic staffs of the Climax Molybdenum Company, a division of Amax Inc., studied the ground water geology of the Henderson mine development area. Detailed geologic records of the Henderson mine were available as a result of the exploration, evaluation and development of the mine. Records of the flow, chemical composition and temperature of the ground water at and near the surface, from the entire mine, from portions of the mine, and from exploration holes drilled in the mine, were kept as the mine was developed. Where possible, ground water pressures in drill holes and changes in pressure with time, were recorded. The geologic, hydrologic and chemical data were correlated. The following conclusions were drawn from the correlations: The ground water in the Henderson mine occurs in fractures in Precambrian igneous and metasedimentary rocks and in a series of Tertiary intrusive rocks. Two zones of ground water were recognized; an active zone, in which the fracture systems are recharged and discharged annually into the surface water system, and a passive zone, in which the fractures were filled with water in the geologic past. Discharge from the passive zone is through mine workings that intersect the fracture systems. Discharge from a fracture or fracture system is initially high but decreased with tire!. The rate of decrease in flow (or pressure) is exponential. By measuring the change in flow with time, it is possible to calculate the amount of flow at some given period of time in the future. Based on changes in rate of flow and pressure, and the geology, and assuming rates of mining of the ore, it will be possible to predict the volumes of water that will have to be handled during the life of the mine and the area around the mine that will be drained by the mining operation.

Jan 1, 1976

By Paul F. Saxton

Introduction As the world economies continue to face an increased demand for natural resources to support growth in the established and developing world, the western mining industry has expanded its operations and funding of mineral developments into new and relatively unexplored regions of the world. Mining companies worldwide, in order to grow in a global economy, are now actively exploring and developing mineral resources in the emerging markets of South and Central America and most recently have expanded activities throughout Asia. South East Asia Resources (S.E.A. Resources) has recognized the vast resource potential offered by countries such as China, India and Indonesia, Asia's main driving forces of economic growth and has made a commitment to be actively involved in the area. These countries rich in mineral resources, represent some of the highly prospective and underexplored regions on earth. Their vast potential has been underestimated because of political reasons and overlooked as Central and South America still continue to be the focus of exploration for many mining companies. Most of these Asian countries have faced a prolonged period of political unrest and it has not been until recently that they have begun to enjoy a relatively stable political climate which has encouraged foreign investment, growth and economic development. These countries are in need of capital to develop their infrastructure and market economies. Their wealth in resources is one of the best methods to achieve their goals. Gold is usually one of the first targets to be extracted from developing economies. Equivalent-sized gold projects tend to cost less to develop and require less supporting infrastructure than base metals. These projects are easier to finance and, most important of all, tend to give a quicker return on investment than that offered by base metals. They also provide the economy with precious foreign exchange, international investment and the technology required to build the country. Following is a graph representing the global re-allocation of the total capital investment on the twenty largest gold projects now under construction with the total for those under construction in 1990.

Jan 1, 1996